Tailoring Carbon Electrode with Ionphobic Characteristic in Organic Electrolyte for High-performance

Tailoring Carbon Electrode with Ionphobic Characteristic in Organic Electrolyte for High-performance Electric Double Layer Capacitor

Xue Yin¹, Jianqi Zhang², Le Yang¹, Wende Xiao³, Lei Zhou¹, Yujing Tang⁴, Wen Yang¹*

1 Key Laboratory of Cluster Science of Ministry of Education, Beijing Key

Laboratory of Photoelectronic/Electrophotonic Conversion Materials, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 100081, P. R. China.

2 CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, CAS Center for

Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing 100190, P. R. China.

3 Key Laboratory of Advanced Optoelectronic Quantum Architecture and

Measurement, Ministry of Education, School of Physics, Beijing Institute of Technology, Beijing 100081, P. R. China.

4 SINOPEC Beijing Research Institute of Chemical Industry, Beijing 100013, P. R.

China.

* Corresponding author.

E-mail addresses: wenyang@bit.edu.cn (Wen Yang)

Figure S1. SEM image of (a) YP-50, (b) YP-F30s, (c) YP- F60s, (d) YP-F90s.

Figure S2. TEM image of (a) YP-F30s, (b) YP-F90s. HRTEM image of (c) YP-F30s, (d) YP-F90s.

Figure S3. EDS-mapping images of YP-50.

Figure S4. Raman spectra of samples.

Figure S5. CV curves measured in the symmetric two-electrode cells with 1 M TEATFB/PC electrolyte at the potential range from 0 to 2.7 V at different scan rate of (a) YP-50, (b) YP-F30s, (c) YP-F60s, (d) YP-F90s.

Figure S6. Galvanostatic charge/discharge curves with (a) 0.2 A g^-1, (b) 1 A g^-1, (c) 2 A g^-1, (d) 5 A g^-1.

Figure S7. Cycling durability at a current density of 1 A g^-1 over 10,000 cycles (a) YP-F30s, (b) YP-F90s.

Figure S8. The conductivity of carbon electrodes of YP-50, YP-F30s, YP-F60s and YP-F90s.

The electrical conductivity of electrodes is an important property for supercapacitor application, it can be seen that the conductivity of YP-50 was treated 30s, 60s and 90s are corresponding to 0.261 S cm^-1, 0.276 S cm^-1 and 0.277 S cm^-1. The electric conductivity of the carbon electrodes is slightly improved after CF₄ plasma treatment, which is due to the doping of fluorine atoms changes the charge properties of original YP-50. Thereby promoting the charge transfer between fluorine and carbon, and leading to higher conductivity.

Table S1. Specific surface area, porosity properties of the samples.

SBET(m²g^-1) V(cm³g^-1)

YP-50 1812 0.85

YP-F30s 1772 0.84

YP-F60s 1725 0.82

YP-F90s 1673 0.79

Table S2. XPS surface elemental analysis of samples.

C O F

YP-50 90.4 9.6 -

YP-F30s 87.08 9.7 3.22

YP-F60s 83.92 9.72 6.35

YP-F90s 82.84 9.36 7.8

Table S3. Summarize gravimetric capacitance density at different current density of samples.

Current Density (A g^-1) Gravimetric capacitance density (F g^-1)

YP-50 YP-F30s YP-F60s YP-F90s

0.2 64 78.8 83.2 75.6

0.5 62.2 76.9 81.6 72.6

1 59.5 74.9 80 71.5

2 54.2 71.7 77.6 69.9

5 40 62.9 71.8 65.9

10 19.2 50.3 66.6 59.7